The invention relates to an injection syringe which is particularly used for medical purposes, the injection syringe including a syringe body, a piston being disposed in the syringe body for displacement therein, and an injection needle being located at the front end of the syringe body.
What is known is an ordinary injection syringe usually used for intravascular injections (for example, a product of the firm "Becton Dickinson" having a volume of 20 ml) and having a cylindrical syringe body, a piston with a piston rod and an injection needle. In most cases a mixture of medical substances is injected with this injection syringe, the mixture containing a minor amount of an active ingredient and a large amount of a diluent.
A disadvantage of this injection syringe is that it is not possible to precisely draw up a low dose of an active ingredient (for example 0.3-0.5 ml) due to the large volume of the injection syringe.
What is also known is an ordinary injection syringe (for example, a product of the firm "Becton Dickinson" having a volume of 1 ml) which also has a cylindrical body, a piston and a piston rod and a injection needle, and which enables a user to draw up a very precise amount of an active ingredient. However, intravascular injections cannot be carried out with this injection syringe, as for most intravascular injections it is necessary to draw up 0.3-0.5 ml of an active ingredient and to mix it with 10-20 ml of a diluent.
The problem underlying the invention is to provide an injection syringe by simple construction with which precise doses of an active ingredient and of a diluent can be drawn up.